7. Project Summary/Abstract Adolescent alcohol use is associated with limited academic performance, career aspirations, eventual adult role attainment, and less engagement in substance-free activities. The proposed project aims to design a developmentally tailored substance use intervention for adolescents using an iterative treatment development process of a daily diary study, focus groups, and an intervention refinement study. Brief substance use interventions for college students have been enhanced using a behavioral economic supplement (Substance-Free Activity Session; SFAS). The SFAS behavioral economic intervention aims to increase the salience of delayed academic and career goals, increase engagement in substance-free activities, and increase the salience of both short and long-term goals in the context of existing alcohol and other substance use. However, less is known about how high school students spend their time, what substance-free activities they engage in and view as attractive and acceptable, and how their goals impact substance use. Utilizing the guidelines of a stage model for intervention development, the study will consist of an iterative treatment development approach to examine a novel SFAS intervention for high school students. The specific aims are as follow: (1) Use event-level daily diary methods to characterize how high school students spend their time in relation to substance use and goals, specifically examining temporal precedence of substance-free activities and substance use (2) Qualitatively assess substance-free activities among high school students, and (3) Examine the feasibility and acceptability of the SFAS for high school students with an intervention refinement study. Findings from the etiologic investigation of Aim 1 and Aim 2 will inform the design of the modified behavioral-economic intervention that is developmentally tailored to suit an adolescent population. This project is viewed as an initial treatment development study that will inform research on prevention and intervention approaches for adolescent substance use and may lead to a larger randomized clinical trial. The applicant will receive training in: (1) the etiology, prevention, and treatment of adolescent substance use, (2) adolescent substance use within a developmental context, and (3) advanced statistical methods. The proposed research and related training activities will provide a foundation for the applicant's program of research toward the establishment of effective, developmentally informed substance use intervention for adolescents.